Gantry Cranes

[swampedout]

Anyone here made a gantry crane?
I was starting with wood but I cant find lumber thats suitably straight so now Im looking at designing one made out of steel pipe. With enough truss, I figure I can make it to lift a couple hundred pounds, nothing crazy.

[Gary Lewis]

I haven't made one, but did look at them at Harbor Freight.  That's the way I'd go if I were getting one.

[FuzzFace2]

If you can get heavy wall pipe you can make one think swing set with out the swings.
They one I made I used to pull many a motor / trany combos and a few cab swaps.
Dave ----

[swampedout]

Im going the pipe route, sorry Gary!

Its actually the reason I decided to go with steel for this project: a metal fabricator down the road from me sells pipe at a great price. I havent measured the wall thickness but it looks good.
A lot of designs, like the HF one, have an I beam across the top but Im probably going to do pipe across the top, maybe two trussed to each other
I-----------I
I   I    I   I
I-----------I

In my reasearch, it seems like a major point of failure was in the middle of the top beam where the load hangs. And since Im not an engineer and cant calculate material strengths, Im going to do a couple bars across the top and over build it every way i can think of.

[Gary Lewis]

What you've diagrammed is effectively an I-beam.  If you can keep the two pieces of pipe the same distance apart they are extremely strong.

[swampedout]

Exactly Gary. I considered getting a real I Beam but the cost for the length I want is probably too much and I can cut and weld better joints for pipe anyways.

I had an Aha moment when I woke up this morning of how to make the posts and top beam seperate into 3 parts by welding the top beam onto a wider diameter pipe that slips over the posts and bolts into place. Plus I can make the height adjustable that way just by creating different bolt hole positions.

[Gary Lewis]

Yes, that would work.  But you might want to have triangular piece above and below the horizontal pipe where it hits the vertical pipe.  It'll give you a lot more welding area and spread the load.

[swampedout]

We are on the same page, Gary. Im going to have triangles reinforcing every corner, maybe multiple on some.
If this crane is going to be lifting hundreds of pounds while Im around it, I cant afford to take shortcuts to build it.
Works been so busy, though I might wait until winter to build it.

[ArdWrknTrk]

Sam, I think the reason gantry cranes use I beam is so you can roll a trolley across them.
I like a chainfall hoist myself, but attaching it to a traveller is important to me.

Just looking at this, because it's apparent I need to pull my engine.... maybe this weekend.

[Gary Lewis]

Jim - I'm glad you said that as it reminded me to say this:  A pipe gantry crane will work if the load is spread.  And a good way to spread the load is with a trolley with wheels designed for that size of pipe.  That way you get a large surface area across which the load will be spread.

But if you just throw a chain around the pipe it is likely to fail as the load is concentrated in one spot.

[Danny G]

What's the Pros and cons of a gantry crane vs a standard rolling shop crane?

[ArdWrknTrk]

I assume you mean an engine hoist (cherry picker)?

Pro:
Much wider stance. Less likely to tip over.
Legs are not under the vehicle.
No hydraulics to bleed down. More steady and precise control.
Traveller (skate) allows you to shift lift point, and move load sideways without moving frame.
More height (depends on frame)
Generally more versatile. Can be used to pick loads out of truck bed, or to pick bed or cab off frame.

Cons:
Takes up more space, and height (not as compact to store, short garage door might not allow passage)
Need to remove hood to pull engine.

[FuzzFace2]

ArdWrknTrk wrote

I assume you mean an engine hoist (cherry picker)?

Pro:
Much wider stance. Less likely to tip over.
Legs are not under the vehicle.
No hydraulics to bleed down. More steady and precise control.
Traveller (skate) allows you to shift lift point, and move load sideways without moving frame.
More height (depends on frame)
Generally more versatile. Can be used to pick loads out of truck bed, or to pick bed or cab off frame.

Cons:
Takes up more space, and height (not as compact to store, short garage door might not allow passage)
Need to remove hood to pull engine.

I used the cherry picker to do both


When one is working by ones self you use what you got
Dave ----

[Danny G]

I now know how i am pulling my bed off and getting into the back yard.

[FuzzFace2]

TheScatch wrote

I now know how i am pulling my bed off and getting into the back yard.

If you are talking how I did it just look out for the piston as I think it hit the bed wall butI did not care as I was cutting it off.
All I wanted was the ribbed metal floor for my flare side bed.

As for moving a full bed I used my garden tractor & trailer to move it out and back into the garage.
I also used straps and hung it from the rafters when building and fitting it to the truck.


Dave ----